DE202011103828U1 - Hydraulic distributor for column percolation plants - Google Patents

Abstract

Hydraulic distributor for column percolation systems for the elution of soils, residues and other grained substrates (also in accordance with DIN 19528), characterized in that a series of valves distributes the eluate to different partial samples (fractions) and the eluate does not come into contact with air during this sample division comes.

Description

Soil excavation, mineral waste and industrial by-products and recycling materials must be tested for the release of pollutants prior to their proper and harmless recycling as construction materials. The new column percolation method is used for this purpose DIN 19528 , with the aid of which the so-called source strength of mineral waste can be reliably determined.

In this method, the granular materials to be examined are introduced into a cylindrical tube (column cylinder) and through a pump from bottom to top with water (template solution) flows through (percolated). The sample liquid (eluate) exiting the column cylinder for several hours is then analyzed according to DIN 19258 subdivided into four subsets (fractions) at fixed intervals in order to be able to examine their pollutant concentrations over time.

Problem 1

The protection specified in claim 1 invention is based on the problem that the sample division has been made on classic fraction collector. These are in most cases devices with a series of open-topped sample tubes, which are successively filled with the help of a donor tube. In this case, the solution is distributed to the various sample vessels either by rotating the vessels under the outlet opening of the dispenser tube (eg by rotation of a sample carousel) or by using an automatically controlled extension arm to successively place the dispenser tube over the vessels set up in so-called racks placed. Both methods have in common that the aqueous sample comes into contact with the ambient air when it leaves the dispenser tube. Even during the subsequent storage of the sample, the vessel is usually open at the top and therefore further in contact with the ambient air.

The problem with this type of sample separation is that the sample composition can change greatly due to air contact (eg, oxidation) and therefore the measured solution concentrations at the end of the experiment (which lasts up to 100 hours) no longer correspond to the original proportions ,

Solution 1

This problem is solved by the use of a newly designed hydraulic distributor in which solenoid valves distribute the incoming solution to the various fractions. The solution flows from the hydraulic distributor through airtight hoses directly into the hermetically sealed sample vessels without coming into contact with the ambient air. In order to divide the accumulating sample quantities of a fraction of up to 18 liters into ergonomically easy to handle units, up to 4 bottles are screwed together via screw caps with airtight hose connections from a fraction size of 5000 ml and are available via communicating tubes (high-quality tubing or V4A cannulas). in connection. These lines are arranged so that when the desired filling level in a bottle is reached, the solution to be passed on is automatically transferred to the next bottle. The last bottle of each fraction has a capillary in the lid of less than 1 mm in diameter and thus ensures the necessary pressure equalization, without producing an air contact relevant for the sample composition.

Problem 2

• 1) die Probenflüssigkeit kommt mit den Bauteilen der Magnetventile in Kontakt. Hierdurch kann es einerseits zur Verunreinigungen der Probenflüssigkeit durch die Pumpenwerkstoffe kommen, andererseits können die in der Probenflüssigkeit gelösten Stoffe an den Pumpenwerkstoffen adsorbiert und dadurch aus der Lösung entzogen werden. In beiden Fällen kommt es zu einer vermeidbaren Veränderung der Probenzusammensetzung.
• 2) Die mediumberührenden Teile der Magnetventile erhitzen sich im geschalteten Zustand, wodurch sich die Probenflüssigkeit erwärmt. Diese Erwärmung kann chemische Reaktionen in der Probenflüssigkeit auslösen und somit eine vermeidbare Veränderung der Probenzusammensetzung nach sich ziehen.
• 3) Bei der Durchströmung herkömmlicher Magnetventile und hydraulischer Verteiler kommt es durch Änderungen des durchströmten Durchmessers zur Ausbildung von Mikrobereichen mit langsamen Strömungsgeschwindigkeiten, welche zur Sedimentation von mit der Lösung transportierten Schwebstoffen führen können. Mögliche Folgen davon sind einerseits die Verstopfung der Ventile und andererseits die Verunreinigung der Probenflüssigkeit durch Sedimentationsreste.

Conventional hydraulic manifolds from automation technology usually consist of a metal block with a series of holes whose opening and closing by means of solenoid valves, the distribution of fluids on various connected lines takes over. The use of such solenoid valves has several disadvantages:

• 1) the sample liquid comes into contact with the components of the solenoid valves. On the one hand, this can lead to contamination of the sample liquid by the pump materials, on the other hand, the substances dissolved in the sample liquid can be adsorbed on the pump materials and thereby removed from the solution. In both cases, there is an avoidable change in the sample composition.
• 2) The wetted parts of the solenoid valves heat up in the switched state, which heats the sample liquid. This heating can trigger chemical reactions in the sample fluid and thus result in an avoidable change in the sample composition.
• 3) With the flow through conventional solenoid valves and hydraulic distributors, changes in the flow-through diameter lead to the formation of micro-regions with slow flow velocities, which can lead to the sedimentation of suspended matter transported by the solution. Possible consequences of this are on the one hand the blockage of the valves and on the other hand the contamination of the sample liquid by sedimentation residues.

Solution 2

• 1) Bei Schlauchquetschventilen kommt es nicht zu einem Kontakt mit den Ventilbauteilen sondern lediglich mit dem Probenschlauch, welcher durch die Betätigung des Ventils geöffnet oder geschlossen wird. Eine durch die Ventilwerkstoffe verursachte Veränderung der Lösungszusammensetzung ist damit ausgeschlossen.
• 2) Die mediumberührenden Bauteile der Schlauchquetschventile erwärmen sich nicht, daher sind wärmebedingte Einflüsse auf die Probenflüssigkeit ausgeschlossen.
• 3) Die Probenflüssigkeit durchströmt allein den Probenschlauch, welcher über die gesamte Länge den selben Querschnitt besitzt. Mikrobereiche mit verminderten Fließgeschwindigkeiten durch Querschnittsänderung innerhalb des Ventils und die Gefahr einer dadurch bedingten Sedimentation von Schwebstoffen sind daher ausgeschlossen. Die rückstandsfreie Durchströmung der Probenschläuche wird außerdem durch ihre vertikale Anordnung in den Schlauchquetschventilen sichergestellt.

These problems are solved by the use of pinch valves and a special arrangement of valves and valve hoses:

• 1) In the case of peristaltic pinch valves, there is no contact with the valve components, but only with the sample tube, which is opened or closed by actuation of the valve. A caused by the valve materials change in the solution composition is thus excluded.
• 2) The wetted components of the pinch valves do not heat up, therefore heat influences on the sample liquid are excluded.
• 3) The sample liquid alone flows through the sample tube, which has the same cross section over the entire length. Microareas with reduced flow rates due to cross-sectional change within the valve and the risk of sedimentation of suspended matter caused thereby are therefore excluded. The residue-free flow through the sample tubes is also ensured by their vertical arrangement in the pinch valves.

To meet these various tasks, the pinch valves are housed side by side in a housing. Above the valves runs a hose with the incoming sample liquid, which is coupled by T-connector with each of the arranged underneath pinch valves. To distribute the sample liquid to the various solution fractions, only one of the valves is opened while the others remain closed.

If contamination of the sample hoses in the valves has occurred despite the measures mentioned, they can be renewed with little effort by a specially prepared replacement hose set. To make this process as simple as possible, hose clamps are attached to the housing of the hydraulic distributor, from which the individual hoses can be easily removed and replaced. In order to facilitate coupling to the sample vessels after replacing the valve tubes, special miniature hose couplings are used, which allow an air-tight and watertight connection of two tubes with a handle without the use of tools.

In the housing of the hydraulic distributor, the sensors important for the control of the column percolation tests can be accommodated (detection of the filling status and pump pressure).

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• DIN 19528 [0001]
• DIN 19258 [0002]

Claims (6)

Hydraulic distributor for column percolation plants for the elution of soils, residues and other granular substrates (also according to DIN 19528), characterized in that a number of valves, the distribution of the eluate on different subsamples (fractions) takes over and the eluate in this sample division not in contact with air comes. Hydraulic distributor for protection claim 1, characterized in that the valves are designed as pinch valves, the sample liquid therefore does not come into contact with pump components and any, induced by pump materials harmful effects on the sample composition are excluded. Hydraulic distributor according to one of the preceding claims, characterized in that the hoses are arranged so that a sedimentation of suspended matter in the region of the valves is excluded. Hydraulic distributor according to one of the preceding claims, characterized in that the entire hose system can be renewed as a spare part with little effort and without the use of tools. Hydraulic distributor according to one of the preceding claims, characterized in that the pump hoses are coupled via easy-to-use special hose couplings without the use of tools to the leading to the sample bottles eluate hoses. Hydraulic distributor according to one of the preceding claims, characterized in that in the housing of the distributor and the sensors for the column level and the pump pressure can be accommodated.